Interpersonal subtypes and change of interpersonal problems in the treatment of patients with generalized anxiety disorder: a pilot study.

Interpersonal problems are highly relevant to the treatment of generalized anxiety disorder (GAD) patients. Previous studies using the Inventory of Interpersonal Problems identified several interpersonal subtypes in GAD patients. In this study, we wanted to replicate earlier findings of interpersonal subtypes in GAD. We investigated whether these interpersonal subtypes are characterized by different types of interpersonal problems and different levels of interpersonal distress, and we further examined whether they differed with regard to improvement of interpersonal problems after short-term treatment. This study is based on results from a randomized controlled trial that investigated short-term treatments in GAD outpatients. For secondary analysis, interpersonal subtypes were identified by cluster analysis and Inventory of Interpersonal Problems profiles were calculated for both the total sample (N = 52) and the interpersonal subtypes using the Structural Summary Method for Circumplex Data. This study confirmed previous results demonstrating the existence of interpersonal subtypes in GAD. Four interpersonal subtypes were identified: Overly Nurturant, Intrusive, Socially Avoidant, and Nonassertive. Short-term treatment significantly improved interpersonal problems (d = 0.46) within the total GAD sample. Interestingly, the effect sizes of the four clusters differed considerably (d = 0.19-1.24) and the clusters displayed different changes in the two circumplex axes Dominance and Nurturance. Our study indicates that change of interpersonal problems needs to be specifically analyzed, even within homogenous diagnostic groups.